Kiln



Nov. 26, 1929. H. M. RoBERTsoN KILN Filed Feb. 25, 1928 2 Sheets-Sheet 1A n ----no----II 2 Sheets-Sheet 2 Q.. h In atto: "aq

nvenro v f u H. M. ROBERTSON KILN Filed Feb. 25, 1928 44% frm Nov. 26,1929.

rag 4 Patented Nov. 26, 1929 vPATENT OFFICE HARRY M. ROBERTSON, FCLEVELAND, OHIO KILN Application led February 25, 1928. Serial No.256,953.

This invention relates to a kiln of the 'tunnel type adapted for burningor heat treating materials 0r bodies formed of clay or like materials orof metal.

'5 One object of the invention is to rovide a kiln of this type soconstructed t at the bodies or materials may be subjected to arelatively high temperature in an oxidizing atmosphere.

Another object of the invention is to provide an improved kiln of themutl'le type wherein provision is made for supplying and circulatinheated air in direct contact with the materials or bodies being treated.

Another object of the invention is to provide an improved tunnel kiln ofthe muille type so constructed that the materials or bodies passingthrough the tunnel are simultaneously subjected to the desiredtemperature by means of radiating heat and heated air in circulationwith the result that all portionsf of the materials or bodies areuniformly and completely treated or conditioned.

i A further object of the invention is to provide an improved tunnelkiln of the muile type capable of treatin materials or bodies in anoxidizing atmosp ere in a rapid and economical manner.

Other objects of the invention will be apparent to those skilled in theart to which my invention relates from the following description takenin connection with the accompanying drawings, wherein Fig. 1 is ahorizontal section of a kiln embodying my invention. v

Fig. 2 is a section on the line 2-2 of Fig. 1.

Fig. 3 is a section on the line 3-3 of Fig. 1.

Fig. 4 is a section on the line 4-4 of Fig. 1..

Fig. 5 is a section on ythe line 5-5 of Fig. 1.

Fig. 6 is a section on the line 6-6 of Fig. l.

Fig. 7 is a section on the line 7 -7 of Fig. 1.

In the drawings, 1 indicates a suitable foundation or basepreferablyformed of suitably reinforced concrete. Mounted on the base 1 arevertical Walls 2, 2, supportinor a roof 3 to form a heating zone or chamer 4, the outer end portion of which constitutes a preheating zone, amain cooling zone or chamber 5 and a secondary cooling chamber 6. EachWall 2 may comprise an inner portion 7 built of suitable refractorymaterial or materials, an intermediate portion 8 of suitable insulatingmaterial and an outer portion 9 preferably formed of brick; and thewalls 2 may be reinforced by vertical beams or struts 10 mounted in thebase 1 and connected by tie rods 11. Each of the outer wall portions 9is provided on its inner surface with a ledge 9n which cooperates withthe upper end of the inner wall portion 7 to support refractory members12 which form abutments for the blocks 13. The blocks 13 have inclinedfaces on which the opposite ends of the inner arch member 14 rest. Thearch member 14 and blocks 13 are formed of suitable refractory materialand they and the members 12 are covered with suitable insulatingmaterial 15, to form the roof 3. 16 indicates the benches formed ofsuitable refractory material and extending from end to end of the walls2 and forming between them a passage or space 1 through the chambers 4,5, and 6. Between the benches 16, the base 1 may be provided with tracks17 for wheel mounted carriers 18, each comprising a frame 18, arefractory base portion 18h and a. holder 18c of refractory material forholding the ware to be treated. Between the heating chamber 4 and maincooling chamber 5 I provide transverse Walls 19, 20, 21, closed at theirinner ends at each side of the passage l by a. vertical wall 22,supported on the adjacent bench 16 near its free edge and closed attheir tops by slabs 23; the wall 19 being connected to the inner wallportion T (see Fig. 1). The spaces between the walls 20, 2'1, 22, formrimary combustion chambers 24, whereas t e spaces between the walls 19,20, 22, 7 form secondary combustion chambers 25 wherein the combustionof the fuel is completed to provide at the inner end of the chamber 4heat therefor. Each primary combustion chamber 24 is connected with 95the adjacent secondary chamber 25 by a plurality of openings or ducts 26formed in the wall 20 (see Fig. 5), each opening being` lined with atubular member capable of resisting the high temperatures resulting 10Ufrom the combustion. The wall forming the bottom of each primarycombustion chamber 24 may be formed with an air intake passage 27 havingits discharge end disposed at the inner portion of the chamber toprovide air for combustion or mixing with the host gases which are tocirculate through the heatin zone 4, as will later appear. Where coal orcoke is used as a fuel, each primary combustion chamber is provided witha suitable grate; where gas or oil is used, the chamber is closed at itsouter end by a refractory wall 28, formed with an opening 29 throughwhich the llame from a burner 30 projects; the fuel being supplied bythe valved pipe 31. The walls 22, which close the inner sides or ends ofthe combustion chambers 24, 25, are formed of a material which has arelatively high coefficient of conductivit so that heat will readilypass through t e wall and by radiation (see arrows in Fi 5) ell'ectivclyheat the ware, whether the atter consists of materials in bulk or shapedbodies, passing through this portion of the kiln.

32 indicates a series of conduits extending longitudinally through thespace above each bench 16, the conduits extending at their Ainner endsthrough the adjacent wall 19 so as to receive heat and hot gases fromthe secondary combustion chamber 25 and at their outer` ends extendinginto a manifold 33, from which the cooled gases are conveyed awa in themanner to be later set forth, the inanifolds being preferably arrangedat or adjacent the entrance end of the chamber 4. As shown in Fig. 4,the conduits 32 are disposed in rows and in staggered, spaced relationto insure contact of air therewith and a mixing of all portions of theair to uniformly and quickly heat it, the air being supplied in themanner to be later set forth. At spaced points along each bench 16, theconduits 32 are supported by transverse walls 34 supported on the benchand through which the conduits extend. 35 indicates a vertical wallextending alon each bench 16 near its side edge and 36 in icates a topmember resting on the upper edges of the walls 34, 35, the wall 35 andtop 36 serving to enclose the adjacent seiies of conduits and thetransverse walls 34 cooperating with the walls 35, 36, to form aplurality of substantially closed spaces 37 between t ein. Betweenadjoining walls 34, the wall 35 is cut away along its top and bottom asshown, to form. inlets 38 and outlets 39 for the air heated by contactwith the conduits 32 and the heat radiating therefrom. As indicated bythe arrows in Fig. 4, the air which is heated by radiation from theconduits 32 or contact therewith passes through the openings 39 anddownwardly into and through the ware on the carriers 18;

the air then passes out through the'openings 38 into tbe spaces 37 whereit is relieated.

The walls 35 may be formed of a material having a relatively highco-eiicient of heat conductivity so that the heat given oil fromchargepipes 41 and these in turn are con-iL nccted to the inlet of acasing 42 enclosing a power driven suction fan or vacuuml creatingdevice. The flow of the air from the chamber 4 through the pipes 40 iscontrolled by valves 43, one` in each of-the discharge pipes and theflow of the cooled gases from the manifolds 33 through the pipes 41 iscontrolled by valves 44, one in each pipe.

Means are provided for supplying air under pressure to certain of thespaces 37 and by preference this air is pre-heated by the ware as itpasses through the main cooling chamber 5, thereby serving to rapidlycool the treated ware and to more quickly as well as economically heatthe air to be conducted through and around the conduits 32.

As shown in Fig. 6, the benches 16 in the chamber 5 support a pluralityof columns or pillars 45 having aligned openings through which piping 46extend, the piping at their outer ends leading through transverse walls47 to receive air from the spaces 48. At their inner ends, the piping 46lead through transverse walls 48 into manifolds 49, which have openingsat their lower ends connected to a duct 5() formed in and extendingtransversely of the base 1. Either or both ends of the duct 50 areconnected by pipes 51 with the inlet of a casing 52 enclosing a bloweror fan driven by the motor 53. The outlet for the casing 52 is connectedto pipes 54, having portions 54 which lead to opposite sides of thechamber 4 and extend longitudinally thereof, as shown in Fig. 1.

Branch supply pipes 55 lead from the pipes 54 into as many of the spaces37 as desired, but preferably into all of the spaces except those nearerthe outer end of the chamber Where the gases flowing through theconduits 32 have cooled to a temperature to make them ineffective forheating the supplied air. Each pipe 55 is provided with a valve ordamper 56 and leads through the adjacent wall 2 and adjacent bench 16and connects with an' enlarged opening or chamber 57 formed in thelatter. The upper end of each chamber 57 is provided with a plate 58formed with perforations which diffuses or breaks the air up into smallstreams for circulation to and around the conduits 32.

By providing along each bench 16 in the heating chamber 4 separatespaces each having an air ontlet at its upper end and au air inlet atits lower end and delivering'l prec heated air to each of the spacesunder pressure, a rapid circulation of the air across and through orbetween the flue conduits to increase the temperature of the air takesplace so that air having a relatively high temperature is directed lntodirect contact with the ware and an induced draft results to insurecirculation through the ware to treat the latter uniformly and quicklyand with minimum consumption of fuel.

The secondary cooling chamber 6 may be provided with manifolds 59extending longitudinally of the benches 16, each having an outletsection 60 leading through the side wall and open at its outer end. Themanifolds have connected to them a series of pipes 61 which leadupwardly at either side of the space for the ware and at their upperends the pipes 61 are bent inwardly for connection with a manifold 62adjacent the roof 3 of the chamber 6 and disposed centrally andextending longitudinally thereof, the manifold 62 having an inlet (notshown) leading through the roof 3'; The inlet may have connected to it asupply pipe leading from a suitable blower so as to force air throughthe pipes 61 for cooling purposes. The chamber 6 is provided with adischarge opening 63 which is closed by a suitable door 64. The tracks17 extend beyond the opening 63, so that the carriers 18, prior to orafter being unloaded may be successively run on to transfer platformssuitably mounted on a vtraekway and then moved to the loading position,and finally transferred to the tracks 17 and moved into the chamber 4.The construction at the discharge end of the kiln is similar to that atits charging or inlet end, but for convenience I have vshown the form ofconstruction and arrangement for handlin the carriers 18- at the inletend only. As illustrated in Fig. 1, the side walls of the kiln areextended as shown at 2, 2*', 2", the walls 21", 2b, forming an inlet orcharglng opening 66, which is closed by a door 67 after the transferplatform with a carrier 18 thereon and mounted on tracks 17 is run intothe extended portion of the kiln withthe tracks on the platform inaligned relation with the tracks 17.

In my construction of kiln it will be noted that the primaryjandsecondary combustion chambers are -disposed at the inner end of theheating chamber 4 and that their inner walls are arranged closelyadjacent to the ware Vas it passes through'the chamber and serve as heattransfer walls to Subject the ware to the l maximum temperature. Bregulatin the flow of the hot gases throng r`the conduits 32 and thesupply of air to the spaces 37, the ware is graduall heated as it movestoward the outlet end o the heatin chamber or to the portion thereinhaving t e highest tem 49 for the air heated in the primary coolingchamber 5 are adjacent and separated by a single wall so that the heatincident to combustion will tend to maintain the air in the manifoldsheated or raise its temperature. It will be obvious that the pipes 54,54l may be suitably insulated.

68 indicates series of pipes disposed on the sides of the benches 16 andserving to convey air through the carrier space 1 below the uppersurface of the benches, whereby the frame and mountings for the wheelsof the carriers will not become overheated.

To those skilled in the art to which my invention relates many changesin construction and widely differing embodiments and applications of theinvention will suggest themselves without de arting from the spirit andscope thereof. y description and the disclosureherein are purelyillustrative and are not intended to be in any sense limiting.

What I claim is:

1. A kiln comprising heating and cooling chambers forming a passagethrough which loaded carriers pass, combustion chambers between saidchambers at opposite sides of said passage, manifolds adjacent the outerend of said heating chamber, a series of conduits for the heat and hotgases disposed at each side of said passage and connected to and leadingfrom each said combustion chamber to one of said manifolds, and wallsenclosing each said series of conduits, said walls having a portiondisposed verticall at the side of the ware on the carriers as t e lattermove through said passage and said vertical portion having supplyopenings arranged opposite the upperportion of the ware and dis chargeopemngs arranged opposite the lower' portion of the ware.

2. A kiln comprising heating and cooling chambers forming a passa ethrough which loaded carriers pass, com ustion chambers between saidheatin and cooling chambers, manifolds adjacent t e outer end of saidheating chamber, a series of conduits for the heat and hot gasesdisposed at each side of said pass e and leading from each saidcombustion c amber to one of said manifolds, and walls enclosing eachsaid series of conduits, said walls having a portion disposed verticallyat the side of the ware on the carriers as the latter move through saidpassage and said vertical portion having supply openings arrangedopposite the upper portion of the ware and discharge openings arrangedopposite the lower portion o the ware, and means for supplying air tothe lower portion of the space enclosing each series of conduits. j

3. A kiln comprising heating and cooling Achambers forming a passa. ethrough which loaded carriers pass, com ustion chambers between saidheating and cooling chambers manifolds adjacent the outer end of saidheating chamber, a series bf conduits for the heat and hot gasesdisposed at each side of said passage and` leading from each saidcombustion chamber to one of said manifolds, and walls enclosing eachsaid series of conduits, said walls having a portion disposed verticallyat the side of the ware on the carriers as the latter move through saidpassage and said vertical portion having supply openings arrangedopposite the upper portion of the ware and discharge openings arrangedopposite the lower portion of the ware, means for supplying air to thelower portion of the space enclosing each series of conduits, and meansat the outer end of said heating chamber for conveying away excess airin said chamber.

4. A kiln comprising heating and coolinv chambers forming a passagethrough whic i loaded carriers pass, connected primary and secondarycombustion chambers at each side of said passage between said heatingand cooling chambers, the inner side walls of said combustion chambersbeing in opposed relation to the ware on the carriers as they passthrough said passage and formed of a material having a relatively highco-eiiicient of conductivity, manifolds adjacent the outer end of saidheating chamber, a series of conduits for the heat and hot gasesdisposed at each side of said assage and leading from one of said seconary combustion chambers to the adjacent manifold, walls enclosing eachsaid series of conduits and formed with an outlet arranged opposite theupper portion of the ware on the carriers and with an inlet arrangednear the lower portion of the ware. t

5. A kiln comprising heatin and cooling chambers forming a passage trough which loaded carriers pass, combustion chambers between saidheating and cooling chambers, manifolds adjacent the outer end of saidheating chamber, a series of conduits for the heat and hot gasesdisposed at each side lof said passage and leading from said combustionchamber to one of said manifolds, walls enclosing each said series ofconduits, said walls including a vertical portion disposed in opposedrelation to the ware on the carriers as the latter move through saidpassage, and transverse walls through which said conduits extend andco-operating with said enclosing walls to form a series of separatespaces said vertical portion of said enclosing walls being formed withan outlet leading from each said space arranged opposite the upperportion of the ware and with a discharge opening arranged `opposite thelower portion of the ware leading into each said space. t

6. A kiln comprising heating and cooling chambers forming a passa ethrough which` loaded carriers pass, com ustion chambers etween saidheating and cooling chambers,

manifolds adjacent the outer end of said heating chamber, a series ofconduits for the heat and hot gases dis osed at each side of saidpassage and lea ing from each said combustion chamber to one of saidmanifolds, walls enclosing each said series of conduits, said wallsincludin a vertical portion disposed in opposed re ation to the ware onthe carriers as the latter move through said passage, and transversewalls through which said conduits extend and co-operating with saidenclosing walls to form a series of separate spaces, said verticalportion of said enclosing walls being formed with an outlet leading fromeach said space arranged opposite the upper portion of the ware and witha discharge opening arranged opposite the lower portion of the wareleading into each said space, and means for supplying air under pressureto each said space.

In testimony whereof, I have hereunto affixed my signature.

HARRY M. ROBERTSON.

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